Wire rope sling



NOV. 1961 w. F. CRANDALL 3,008,287

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14f fay/162's 3,008,287 WEE ROPE SIJ G Walter F. Crandall, St. Joseph,Mo assignor to Wire Rope Gotporation of America, St. .Ioseph, M0,, acorporation of Connecticut Filed Mar. I6, 1959, No. 15,384- 6 Glairns.(til. 57142) This invention relates to a material hoisting or handlingsling.

A particular feature of the present invention is the method of makingslings having varying cross-sectional configurations and physicalcharacteristics whereby the sling has enhanced strength and wearingqualities.

Wire ropes are usually made from a plurality of primary composite wirestrands wound or twisted upon each other. In turn, each strand comprisesa plurality of individual secondary wires similarly wound or twistedabout each other. When used for hoisting or for material handling, asling is made of such wire rope by forming a loop at either end. In thepresent invention this tear-shaped eye or loop is formed by firstseparating one of the primary ropes that make up the base fabric fromother primary ropes at a point removed from the free end of the fabric.The extent or length of this separation is sufiicient to form thedesired area of eye upon forming the loop. The end of this separatedrope is now re-entered upon the remaining unseparated ropes which havebeen formed into a loop and rewound with the same about the loop toabout the point of initial separation of the ropes. This re-entering andrewinding is carried out with the separated primary ropes being spirallywound in the opposite direction to that in which the other ropes arelooped, and its re-entered and rewound portion extends to about thepoint of initial separation of the primary ropes, as stated. The freeends of the loop constituted by the other primary ropes terminatelikewise substantially at this point of separation. That is, at the freeend of the separated primary rope and the free end of the remainingprimary ropes, these ends of all of the primary ropes are adjacent tothe base fabric and these free ends are entwined with the base fabricwith their free ends protruding. This construction is now tightlyclamped together and held by a usual band or ferrule so that the loopwill additionally be prevented from becoming disengaged at this po nt ofjuncture. In brief, since the separated primary rope extendscontinuously in one direction to the point of juncture and the remainingprimary ropes extend continuously in the opposite direction to the pointof jmieture, and the respective ropes are re-entered and rewound uponeach other substantially throughout the length of the looped portion, itis ditlicult, if not impossible, for the loop to be opened at the pointof juncture unless the fabric breaks. Of course, the usual clamp orferrule enhances this holding power and prevents the free ends fromslipping.

It is thus a secondary primary object of the present invention toprovide a loop or sling in which entire dependence on a ferrule forclampin of the end of all of the ropes of the loop to the base fabric inthe usual manner is eliminated. Instead, a construction is provided inwhich one or more ropes of the base fabric cannot be separated in theclamping area should the customary ferrule become loosened. This is notthe case in conventional forms of slings or hoist loops as stated, whereall of the free ends of the wire or cable are clamped to the base fabricat the point of juncture by the ferrule. That is, there is always thelikelihood that the free ends would become disengaged from the clampingmeans or the ferrule will slip under the weight or pressure to which thesling is subjected in use.

The invention and novel features thereof will be made EEG clear from thefollowing description and the accompanying drawings, in which:

FIGURE 1 is a side elevational view of the base fabric made inaccordance with this invention;

FIGURE 2 is a side elevational view of the base fabric of FIGURE 1, butshowing one of the component ropes separated from the others;

FIGURE 3 is a side elevational view of the base fabric of FIGURE 2showing the loop formation, and particularly showing the separated ropere-entered upon and rewound with the remaining ropes to extend in adirection opposite the direction in which the loop is being formedtoward the point of initial separation;

FIGURE 3:: is a fragmentary view of the completed loop of FIGURE 3showing the free ends of the base fabric ropes prior to their beingbound to the base fabric, the said free ends being entwined with thebase fabric and their protruding ends being entwined with each other,the point of juncture being at about the point of initial separation, asshown, and a band or ferrule shown in FIGURE 4 clamping the base fabricand free ends at the point of juncture;

FIGURE 4 is an elevational view of one end of a sling;

FIGURE 5 is a cross-sectional view taken along line 55 of FIGURES 1 and3 showing the composite structure of the primary ropes 22, 24, 26 andsecondary strands 2S and the tertiary wires 36 FIGURE 6 is a sideelevational view corresponding to FIGURE 2, but showing additionallengths of wire rope inserted in one end of the base fabric;

FIGURE 7 is a side elevational view showing one step in forming thereinforced material handling loop of FIG- URE 6;

FIGURE 8 is a side elevational view showing the formation of the loopfrom the altered base fabric of FIG- URE 7;

FIGURE 9 is a cross-sectional view taken along line 99 of FIGURE 8 andgenerally similar to FIGURE 5, but showing also two additional ropes 38and 40';

FIGURE 10 is a view generally corresponding to FIG- URE 6, but showing afurther modification of the base fabric; 7

FIGURE 11 is a view generally corresponding to FIG- URE 7, but showingthe modified base fabric of FIG- URE 10;

FIGURE 12 is a side elevational view showing the formation of the loopof the modified base fabric of FIG- URE 11:

FIGURE 13 is a cross-sectional view taken along line I3i3 of FIGURE 12;and

FIGURE 14 is a view corresponding to FIGURE 5, but showing still anothermodification of this invention.

Referring now to the drawings and in particular to FIGURES 1 through 5,there is shown the basic form of the present invention, namely, a basefabric having a loop or eye at one or both ends to form a sling. InFIGURE 1, the base fabric is indicated at 24) and comprises a pluralityof individual primary composite wire ropes 22, 24 and 2 6 interwoundabout each other along a common axis as also shown in FIGURE 5.

In FIGURE 5, there is shown, for illustrative purposes only, that eachbase fabric rope 22, 24 and 26 comprises a plurality of smaller diameterWire strands 23 inter- Wound about each other and wherein each of thesmaller strands 23 in turn is made from a plurality of even smallerdiameter wires 30. It is to be understood, of course, that theconstruction of the base fabric ropes 2 2, 24 and 26 may be of. the manyvarious known types of wire rope currently in use.

Referring to FIGURES 2, 3 and 4, in forming the basic material handlingeye or loop 32, one of the base fabric ropes 26 is separated from theother base fabric ropes 22 and 24 at a point 34 removed from one end ofthe base 20. The free end portions of the base fabric ropes 22, 24 and26 extend beyond the point of separation '3 of the base fabric, forexample, approximately twice the length of the finally desired length ofeye or loop 32. The separated primary rope 26 and the other primaryropes 22 and 24 are then returned and inter wound with each other, asshown in FIGURE 3, to form a material handling loop or eye 32 integralwith the base fabric 20. The free ends of each of the ropes 22, 24 and26 are then disposed adjacent the point 34 of the base fabric 20 and maybe there crossed over, interwoven or otherwise engaged as shown inFIGURE 3a, and suitably bound to the base fabric 20 adjacent the pointof juncture 34' by means of a ferrule or sleeve member 36. With thebasic sling loop thus formed, it will beseen that the loop portion 32has a cross-sectional configuration, as shown in FIGURE 5, which is theidentical crosssectional configuration as the original base fabric 20from which the sling is made. It will be noted, as shown in FIGURES 2and 3, that the primary rope 26 is separated at the point 34 andreturned to extend counterclockwise in spirally wound relation upon theremaining primary ropes 22, 24, while the latter are returned to extendclockwise. Thus, the respective ropes are interwound and twisted whileextending in opposite directions and with their free ends terminating at34', as shown in FIGURE 30, adjacent the point of separation 34. There,the free end portions are interwound with the base fabric and thisjuncture and the protruding portions of the free ends are clamped intheir crossed over or twisted condition by the ferrule 36.

By following the above-described basic method for forming the loop 32and the base fabric 20 and by adding additional lengths of Wire ropewithin the base fabric 20 and loop 32, various modifications of thematerial handling sling may be made in accordance with this invention toprovide slings having stronger physical properties and varyingcharacteristics, depending upon the load which is to be handled by thesling composed of base fabric 20 and loop or loops 32..

Such a modified sling is disclosed in FIGURES 6 through 9 in whichFIGURE 6 illustrates a base fabric 20 generally corresponding to thebase fabric of FIG- URE 1 wherein one of the base fabric ropes 26 hasbeen unlaid or'separated from the other base fabric ropes 22 and 24. Inthis particular modification, an additional wire rope 38 of the samecharacter as the base fabric ropes has one of its ends interwoven orsuitably inserted at the point 34 of the base fabric 20, whichessentially represents the end of the original base fabric beforemodification in accordance with this invention. A further addition ofrope 40 having a different characteristic or structure or differentcross-sectional configuration than that of each of the base fabric ropes22, 24

and 26'is similarly inserted at the end 34 of the base fabric 20. Eachof the wire ropes 38 and 40 is substantially coextensive with the basefabric ropes 22, 24 and 26 throughout the length of the sling and extendbeyond the point 34 of the base fabric 20 to the free ends of theprimary ropes. In forming this particular loop the additional rope 38 iswound about the separated primary. rope 26 and the additional differentdiameter wire rope 40 serves as a core aboutwhich the other primaryropes 22 and 24 are wound, as shown in FIGURE 7. With the ropes of thebase fabric 20 thus modified, the separated primary rope 26 with theadditional rope 38 wound thereabout, and the other primary ropes 22 and24 with the additional rope 40 as a core are returned about andinterwound with each other to form a loop 42 in the same manner as wasthe loop 32 formed; The free ends of all of the ropes 22, 24, 26, 38and-40 are then disposed adjacent the point 34 of the base fabric 20, asdescribed above, and may be suitably boundthereat by means of theferrule or sleeve 36 in the manner shown in the previous figures. Themodified loop 42 thus formed now comprises four ropes 22, 24, 26 and 38,all having the same cross-sectional configuration and physicalproperties as the other, and a core rope 4t arranged within the foursimilar ropes.

There is shown in FIGURES 10 through 13 another modification of thematerial handling sling which has in the sling portion five lengths ofwire rope, each having the same configuration as the other and eachbeing the same as the individual primary Wire ropes 22, 24 and 26 whichconstitute the base fabric 2!). The formation of this modified form ofsling is accomplished by first insertropes 22, 24, and 26 throughout thelength of the sling and extend beyond the point 34 of the base fabric 21to the free ends of the primary ropes. As shown in FIGURE 11 the nextstep in the formation of the loop of this modification of the sling isto interwind the ropes 38 and 44 about the additional different diameterrope 40 which will serve as a core, the primary ropes 22, 24 and 26 arewound about'each other. The intertwined ropes 33 and 44 and the corerope 4d are then Wound about the primary ropes 22, 24 and 26 to form theloop 46 as shown in FIGURE 12. As in the case of the previouslydescribed modified loops 32 and 42, the free ends of each of the ropeshave portions which are interwound with the base fabric and protrudingportions inter-wound with each other. At this point of juncture 34' theend portions are additionally bound to the base fabric 24) and eachother by means of the ferrule or sleeve 36, as described. The resultantloop 46 now comprises five lengths of rope 22, 24, 26, 38 and 44, eachhaving the same cross-sectional configuration and physicalcharacteristics as the other and wound about a core of rope 46 having adifierent cross-sectional configuration and physical characteristicsthan the others. Thus, it will be seen that the base fabric 20 may bestill further modified by the interwinding of additional lengths of ropewith the ropes that constitute the base fabric and the insertion of acore rope to provide a strong material handling or hoisting sling.

Although there has been shown here and described a base fabric 20comprising three primary ropes 22, 24 and 26 which are in turn made froma plurality of smaller diameter strands 28 and 30, respectively, thebase fabric may take various forms and the practice of this invention isnot limited to a basefabric comprising three wire ropes. Any base fabricwhich has more than one wire rope may be altered in accordance with thepresent invention without departing from its teachings, a base fabricmade from three individual ropes here being shown and described forillustrative purposes only.

Various modifications of the above described slings may be accomplishedby adding to the base fabric 20 additional lengths of wire rope of thesame cross-sectional configuration as the primary ropes 22, 24, and 26and the insertion of an additional different diameter wire rope similarto 40 as a core to produce sling bodies with the cross-sectionalconfiguration as shown in FIGURES 9 and 13. The further modification ofthis invention is shown in FIGURE 14. The drawing illustrates a crosssectional View of three lengths of a base fabric 20 interwound abouteach other on a common axis to form a new sling. A loop may be formedusing the compound base fabric in the same manner as the loop 32 wasformed as illustrated in FIGURES 1 through 5. That is one of the lengthsof the base fabric 2tlis unwound to a point, as point 34 in FIG- URE 2,removed from one end of the compound fabric and the free end of theremaining interwound lengths of the base fabric are looped andinterwound with the single lengths to form a loop such as 32 shown inF16 URE 4. This looping and interwinding using the compound base fabricis accomplished in the identical manner as the looping and winding shownin FIGURES 2 and 3 where a single length of base fabric is used to formthe loop.

The invention, it will be observed, essentially comprises three wireropes having a plurality of wire strands interwound about each otheralong a common axis to form a base fabric 20, a loop $2 at one or bothends of said base fabric, said sling including at least one of said basefabric ropes 26 separated from the base fabric 20 at a point 34 removedfrom the adjacent end of the fabric enough to form a loop of the desiredarea and thereafter returned and wound about other of said base fabricropes 22, 24 in one direction extending from said point to substantiallythe free end of said separated rope at 34', and the other of said basefabric ropes 22, 24 being wound about said separated rope 26 andextending in the opposite direction, from said point of separation 34,to substantially the free end of said other rope 26 at 34, the free endsof all of said ropes being joined with each other and said base fabricadjacent the point of separation, as by a band or ferrule 3 6.

In general, the slings of this invention are produced from a base fabricprepared by interwinding a plurality of wire ropes about a common axisto form a base fabric 29, by a method comprising separating one of saidropes 26 from said other rope at a point 34 sufhciently removed from oneend of said base fabric to form a loop 32 of desired area, returning andinterwinding said separated rope 26 with remaining strands 22, 24 in adirection toward the point of separation 34 with its free endterminating adjacent said point; returning and rewinding said otherropes 22, 24 with said separated rope 26 in the direction opposite thatof the separated rope 26 until the free ends of said other ropes areadjacent the point 34 of separation, and with the free ends of all ofsaid ropes being disposed adjacent said point 34 of said base fabric,and joining at 34 the free ends of all of said ropes with each other andsaid base fabric adjacent the said point of separation.

It thus will be seen that there has been provided by this invention arope sling in which the various objects hereinbefore set forth, togetherwith many practical advantages, are successfully achieved. As variouspossible embodiments may be made of the novel features of the aboveinvention, all without departing from the scope thereof, it is to beunderstood that all matter hereinbefore set forth is to be interpretedas illustrative, and not in a limiting sense.

What is claimed is:

1. The method of forming a material handling sling from wire ropeprepared by interwinding a plurality of wire ropes about a common axisto form a base fabric comprising: separating one of said ropes from saidother ropes at a point sufficiently removed from one end of said basefabric to form a loop of desired area, separating the other of saidropes and inserting an additional wire rope, interwinding said separatedropes about said inserted additional rope, said additional rope forminga core returning and interwinding said separated rope with remainingropes in a direction toward the point of separation with its free endterminating adjacent said point; returning and rewinding said otherropes with said separated rope in the direction opposite to that of theseparated rope until the free ends of said other ropes are adjacent thepoint of separation, and the free ends of all of said ropes beingdisposed adjacent said point of separation of said base fabric, andjoining the free ends of all of said ropes with each other and said basefabric adjacent the said point of separation.

2. The method as defined in claim 1 further comprising the step ofinterwinding a second wire rope about said first separated rope alongthat portion of said rope extending from said point of separation to thefree end thereof.

3. A sling fabric comprising a plurality of wire ropes interwound abouteach other along a common axis to form a base fabric, a loop at one orboth ends of said fabric, said loop including at least one of said basefabric ropes separated from said base fabric and interwound about theothers of said base fabric ropes, said separated rope extending in woundrelation in one direction adjacent the point of separation from saidbase fabric to its free end, a first additional wire rope about whichsaid base fabric ropes are wound and a second additional wire ropeinserted and interwound with said separated rope, said first and secondadditional wire ropes being substantially coextensive with the rope ofthe base fabric for the full length of the sling.

4. A sling fabric as defined in claim 3 wherein the first additionalwire rope is of a smaller diameter than the rope of said base fabric.

5. A sling fabric as defined in claim 3 in which the second additionalwire rope is of the same diameter as the ropes of said base fabric.

6. A sling fabric comprising: a plurality of wire ropes interwound abouteach other along a common axis to form a base fabric, each ropecomprising a multiplicity of interwound strands which in turn comprise.a multiplicity of wires; a loop at at least one end of said base fabric,

said loop having at least one of said base fabric ropes including saidmultiplicity of strands and Wires separated from the base fabric at apoint removed from the adjacent end of the rope enough to form a loop ofthe desired area and thereafter returned and wound about the remainderof said base fabric ropes in one direction extending from said point ofseparation to substantially the free end of said separated rope, and theremainder of said base fabric ropes being wound about said separatedrope and extending in the opposite direction from said point ofseparation to substantially the free end of said other rope, the freeends of all the said ropes being joined with each other and said basefabric adjacent the point of separation.

References Cited in the file of this patent UNITED STATES PATENTS1,334,244 Howe Mar. 16, 1920 1,839,698 Novotny Jan. 5, 1932 2,454,592Budzinski Nov. 23, 1948 2,463,199 Peterson Mar. 1, 1949

